Int. J. Adv. Eng. Pure Sci. 2020, 32(2): 192-196 DOI: 10.7240/jeps.631637 Corresponding Author: Zeynep TAŞLIÇUKUR ÖZTÜRK, Tel: 0216 3952630(3160), e-posta: ztasli@gmail.com Submitted: 10.10.2019, Revised: 26.12.2019, Accepted: 19.02.2020 RESEARCH ARTICLE / ARAŞTIRMA MAKALESİ Sintering of Seydişehir Alumina from Sol Gel Method with TiO2 Addition TiO2 ile Sol Jel Kaplanmış Seydişehir Alüminanın Sinterlenmesi Zeynep TAŞLIÇUKUR ÖZTÜRK 1 , Selin ENGÜRLÜ 2 , Nilgün KUŞKONMAZ 3 1 National Defence University,Turkish Naval Academy, Mechanical Engineering Department,34942, Istanbul, Turkey 2,3 Yildiz Technical University, Faculty of Engineering, Metallurgy and Materials Engineering, Davutpasa Campus, Esenler, 34210, Istanbul, Turkey Abstract In this study, we report the sinterability of Seydişehir α-Al2O3 by coating TiO2 colloidal particles by sol-gel method. In this context, efforts have been made to decrease the amount of impurities with washing process, to stabilize transformation with calcination and to reduce grain size by jet-mill grinding. It is aimed to increase the density of Al2O3 by coating TiO2 by sol-gel method. The ceramic powders were dry-pressed, they were sintered at 1580 0 C for different hours(1h, 3h and 6h). The role of TiO2 content and sintering time on the microstructural properties and density of final products were investigated. Keywords: Al2O3, TiO2, Sintering, Sol-Gel Öz Bu çalışmada, Seydişehir α-Al2O3, TiO2 kolloidal parçacıklar ile sol-jel yöntemiyle kaplanmış ve α-Al2O3’nın sinterlenebilirlik özellikleri rapor edilmiştir. Yıkama işlemi ile kirlilik miktarını azaltmaya, kalsine ile dönüşümü stabilize etmeye ve jet değirmen öğütme ile α-Al2O3’nın tane boyutu azaltılmaya çalışılmıştır. TiO2 sol-jel yöntemi kullanılarak kaplama ile Al2O3'ün yoğunluğunun arttırılması amaçlanmıştır. Seramik tozları kuru preslenmiş, farklı saatler (1 saat, 3 saat ve 6 saat) boyunca 1580 0 C'de sinterlenmiştir. TiO2 içeriğinin ve sinterleme süresinin nihai ürünün mikroyapısal özellikleri ve yoğunluğu üzerindeki rolü araştırılmıştır. Anahtar Kelimeler: Al2O3, TiO2, Sinterleme, Sol-Jel I. INTRODUCTION Alumina is a known ceramic material because of its high temperature stability, chemical inertness, strength, hardness, tribological, electrical and optical properties. The properties of alumina-based ceramics depend on the final microstructures which are affected by the characteristics of the starting powders[1-7]. Seydişehir Alumina has large particle size distribution and high impurity content. In recent years, many researchers focus on improving its sinterability properties by reducing the Na content, grinding and ceramic coating[2-4]. The ceramic coating improves the distribution of sintering aids, and also modify the rheological and consolidation behaviour of a ceramic suspension[5,8]. Sol-gel process is an useful method for the preparation of amorphous and structurally ordered materials and allows the synthesis of powders with a more controlled structure and morphology. It also improves the reactivity of the synthesized material such as porosity and surface area, to obtain homogeneous matrices[9-11]. Sol-gel method is highly preferred due to its low process cost, easy control of composition and relatively low calcination temperature[8,12,13]. The solid-state method requires a sintering process at high temperatures with a long holding time. This process may lead to sodium loss and exaggerated grain growth, which are deleterious to the mechanical strength. In order to decrease the sintering temperature, sol –gel method has been studied. The mixed oxides of TiO2 and Al2O3 is a good alternative to overcome the problems of